Abstract: Electrostatic spark is a weak fire source, and its generation,accumulation and discharge process are complex. It is difficult to investigate and obtain evidence, and it is generally necessary to identify it after excluding the possibility of other fire sources. Based on the cause identification of a fire accident which is seemingly simple but complex, through investigation and field experiments, qualitative analysis and quantitative calculation were carried out to restore the truth. How to accurately identify the electrostatic fire was described, and the occurrence conditions, characteristics, energy and identification points of various types of electrostatic fire were summarized.

Key words:  fire investigation, electrostatic fire, brush discharge